[cr0sh]

I don't believe I've ever been in any hardware store that sold hydrofluoric acid in any concentration. Care to expand on what you meant?

Now - hydrochloric acid or sulfuric acid - both those (and some other relatively nasty chemicals) can be easily purchased at many hardware (and other) stores; the first is commonly known as "muriatic acid" (pool acid), while the second is sold (usually at auto parts stores, but there are some hardware stores that sell it too) for lead-acid battery "replenishment" (if the acid in them becomes too diluted from "topping up" with distilled water over time).

But HF? No - I certainly can't see where that would be allowed to be sold in any concentration to the ordinary public...

[detaro]

In low concentration, it's in various cleaning products, rust removers, that kind of thing. In some places, you can buy glass etching cream which also contains HF.